Web server farms, load-balancing clusters, tightly-coupled compute clusters, and other groups of linked computers which work closely together and outwardly present the appearance of a single more powerful resource are referred to herein as “computational clusters”. The electrical power used by a computational cluster to produce a given result may vary, depending on how efficiently the computational cluster is implemented and operated. For example, improved algorithms may allow computation of the same given result using fewer processing cycles, fewer memory accesses, and/or more localized (and faster) memory accesses. Similarly, optimizations may be possible which remove code execution paths or blocks of code that do not contribute to the given result. Hardware improvements may reduce chip or board power consumption without degrading performance. Measures which are not specific to the hardware or software of the computational cluster may also improve overall efficiency, such as reductions in the power consumption of air conditioning that keeps the cluster within acceptable operating temperatures.